Kasumi, also known as::: kunoichi of Destiny::: is a female ninja skilled in the Mugen Tenshin Style Ninjutsu. He became the 18th Master of the Mugen Tenshin Ninja Clan, but she fled in order to follow the Dead or Alive tournament. There, he wanted to defeat Raidou, which paralyzed her brother Hayate. Leaving a secret ninja clan made a nukenin ::: runaway shinobi ::: runaway ninja who will be hunted clann. He was obliged to live on the run from former colleagues who wanted to hunt down and just retribution for her act of treason. Kasumi finally can kill Raidou and wins the tournament.
After Kasumi won his first tournament (and killing Raidou), he was arrested by DOATEC as an experiment to create a clone of hers made, called Kasumi X. He managed to escape (defeating her clone, Kasumi X, in the process) and trying to return to his village, but he was not allowed to return to his village, because she is a runaway shinobi, ninja, and an honor that will never rejoin their respective clan . Kasumi met with Ein think that it was her brother Hayate while they were both similar. Kasumi and Ein then battle one another.
Now labeled as "traitors" in her village, Kasumi has constantly pursued by the murderers of the clan, not a single day passed without the efforts of his life. However, Kasumi still want to see her brother Hayate, and entered the third tournament to see him one last time.